Obtain, store, transport, and culture human esophageal tissue following surgical resection and/or immediate autopsy. Study the morphological and cytochemical characteristics of epithelium (removed at zero-time) in normal, premalignant, and malignant states. Determine conditions and develop methods to maintain esophageal tissue for long periods of time in culture in vitro. These cultures will be examined using high resolution light and electron microscopy. Study the morphological and cytochemical characteristics of epithelium in normal, premalignant, and malignant states maintained in organ culture.